Invasive aspergillosis (IA) continues to cause morbidity and death in medically immune compromised patients, largely because we lack sensitive diagnostic tests that are easy to use during high-risk periods. We discovered that fungal galactofuranose?containing antigens are excreted in urine of infected animals and people, using a novel monoclonal antibody (mAb476). In a phase I STTR, we engineered a lateral flow device (LFD) called AspUTest, and performance was tested using urine samples obtained from patients with suspected and confirmed IA. Results showed >90% sensitivity and specificity, meeting predefined metrics for continued development. This Phase II application is designed to meet the following Specific Aims: 1.To optimize production of the AspUTest device; 2. To determine performance characteristics of AspUTest as an aid to diagnose invasive aspergillosis using batched samples obtained from patients with hematological malignancies; and 3. To validate and test the performance of AspUTest in clinical microbiology laboratories. Meeting these aims will enable submission for FDA clearance of AspUTest, marking an important advance towards decreasing IA morbidity with expanded availability of a low cost, easy to use urine diagnostic.